How do you get the square root in Ada? - ada

Question

So I have been given an assignment to read in a file put the numbers into two matrices, multiply the matrices, and finally put the output into a .txt file.
I have never used Ada before and I figured it would be a good challenge. I am stuck in trying to determine the bounds for the two separate arrays.
This is what I currently have:
currentSpread := I;
g := Ada.Numerics.Generic_Complex_Elementary_Functions.Sqrt(I);
while J < g loop
if(I mod J = 0) THEN
if(currentSpread > ((I/J - J)/2)) THEN
currentSpread := ((I/J - J)/2);
arrayBounds := J;
end if;
end if;
J := J + 1;
end loop;
The problem I am having is with the sqrt function. I want to find the factors for the best bounds of the matrix multiplication and this was the only way that I thought to implement it.
The error I am getting is:
invalid prefix in selected component "Ada.Numerics.Generic_Complex_Elementary_Functions"
Thanks a lot for any help.
--Update
Full Code as requested:
with Ada.Text_IO;use Ada.Text_IO;
with Ada.Integer_Text_IO;
with Ada.Numerics.Generic_Complex_Elementary_Functions;
with Ada.Numerics.Generic_Elementary_Functions;
with Ada.Numerics.Complex_Elementary_Functions;
with Ada.Numerics.Generic_Complex_Types;
procedure Main is
dataFile : File_Type;
resultFile : File_Type;
value : Integer;
I : Integer := 0;
J : Integer;
currentSpread : Integer;
arrayBounds : Integer;
g : Integer;
begin
Ada.Text_IO.Open(File => dataFile, Mode => Ada.Text_IO.In_File, Name =>"C:\Users\Jeffrey\Desktop\data.txt");
while not End_Of_File(dataFile) loop
Ada.Integer_Text_IO.Get(File => dataFile, Item => value);
Ada.Integer_Text_IO.Put(Item => value);
Ada.Text_IO.New_Line;
I := I + 1;
end loop;
Ada.Integer_Text_IO.Put(I);
I := I/2;
J := 1;
currentSpread := I;
g := Ada.Numerics.Generic_Complex_Elementary_Functions.Sqrt(I);
while J < g loop
if(I mod J = 0) THEN
if(currentSpread > ((I/J - J)/2)) THEN
currentSpread := ((I/J - J)/2);
arrayBounds := J;
end if;
end if;
J := J + 1;
end loop;
declare
type newArray is array(Integer range <>, Integer range<>) of Integer;
X : Integer := J;
Y : Integer := I/J;
Arr1 : newArray(1..Y, 1..X);
Arr2 : newArray(1..X, 1..Y);
finAnswer : newArray(1..X, 1..X);
begin
for z in 1 .. X loop
for k in 1 .. Y loop
Ada.Integer_Text_IO.Get(File => dataFile, Item => value);
Arr1(z, k) := value;
end loop;
end loop;
for z in 1 .. Y loop
for k in 1 .. X loop
Ada.Integer_Text_IO.Get(File => dataFile, Item => value);
Arr2(z, k) := value;
end loop;
end loop;
for l in 1 .. X loop
for m in 1 .. Y loop
for n in 1 .. X loop
finAnswer(l, n) := finAnswer(l, n) + Arr1(l, n)* Arr2(n, m);
end loop;
end loop;
end loop;
end;
Ada.Text_IO.Close(File => dataFile);
end Main;
I am using the square root exclusively to figure out the factors of a number nothing else. How I have it set up now is it will go up to the square root and then it will take the smallest spread of the factors. I do not care about rounding errors or anything else if it isn't a perfect square it can round either way.
Thanks.

Answer 1

Generic_Complex_Elementary_Functions is a generic package. It cannot be used directly. That is why the compiler gives you an error on this line:
Ada.Numerics.Generic_Complex_Elementary_Functions.Sqrt(I);
To use it, you have to instantiate the generic Generic_Complex_Types with the floating-point type you want to use, and then instantiate Generic_Complex_Elementary_Functions with an instance of Generic_Complex_Types. Fortunately, you don't have to go through all that if you're willing to use the built-in type Float; the language provides Ada.Numerics.Complex_Elementary_Functions for you, that uses Float as the floating-point type, or Ada.Numerics.Long_Complex_Elementary_Functions that uses Long_Float if your compiler vendors support it.
However, I don't think you want to use Complex anything. That deals with complex numbers, and I doubt that you want to use those. Use Ada.Numerics.Elementary_Functions (or Long_Elementary_Functions), which deal with real numbers.
Finally, even this isn't going to work:
Ada.Numerics.Elementary_Functions.Sqrt(I)
if I is an integer, because the argument type needs to be a Float. You'll have to use a type conversion.
Ada.Numerics.Elementary_Functions.Sqrt(Float(I))